Railway truck



D. L. TOWNSEND 2,102,102

RAILWAY TRUCK Dec. 14,1937.

Filed Jan. 2, 1934 4 Sheets-Sheet l Dec. 14, 1937. D. L. TOIWNSEND RAILWAY TRUCK Filed Jan.` 2, 1954 4 Sheets-Sheet 2 I INVENTOR Dona/A 7560/759@ BY Al oRNEY Dec. l4, 1937. I D, L TOWNSEND 2,10202 RAILWAY TRUCK Filed Jan. 2, 1934 4 Sheets-Sheet 5 l INVENTOR Uova/d 75m-@Send Dec. 14, 1937. D` 1 TOWNSEND 2,102,102

` RAILWAY TRUCK Filed Jan. 2, 1934 4 Sheets-Sheet 4 /ge /Zge i INVENTOR J5@ 15e if@ ,'yafm/dljw/ysead BY ,1 l i .-i AORNEY Patented Dec. v14, 1937 2,102,102 RAILWAY TRUCK Donald L. Townsend, Rochester, N. Y., -assignor to The Symington-GouldCorporation, a cor' poration of Maryland Application January 2, 1934, Serial No. 704,958

26 Claims.

'Ihis invention relates to railway trucks and, more particularly, to nests of springs for supporting truck bolsters, and the spring plates for said nests.

The principal object of my invention, generally considered, is the provision of railway trucks in which the holsters are supported from asso elated side frames by means of nests of springs involving leaf or elliptic springs associated with helical or coil springs, and employing improved spring plates, preferably formed of cast metal, or other cast means, for holding the springs and the nests in proper relation with respect to one another and the associated frame, said plates being particularly adapted to more positively retain the bands of the elliptic or leaf springs in normal position. V

Another object of my invention is the provision of cast spring plates or caps adapted for use with nests of springs involving both elliptic or leaf springs and helical or coil springs.

Other objects and advantages of the invention relating to theparticular arrangement and construction of the various parts will become apparent as the description proceeds.

Referring to the drawings illustrating my in vention, the scope whereof is defined by the appended claims:-

Figure 1 is a fragmentary side elevational view of a railway truck embodying my invention.

Figure 2 is an elevational view, with the upper spring plate shown in vertical section, and the adjacent set of helical springs removed, ofthe nest of springs shown in Figure l detached from the truck and looking in a direction at right an-` gles to that of Figure 1.

Figure 3 is a plan of the nest of springs shown in Figures 1 and 2, a portion of the upper spring plate being broken away and the associated helical springs only fragmentarily illustrated.

Figure 4 is a detail plan, on a larger scale, of one of the interchangeable spring plates shown in Figures 1, 2 and 3.

Figure 5 is a partial end elevation and partial sectional view on the line 5 5 of Figure 4, looking in thedirection of the arrows.

Figure 6 is a partial side elevation and partial vertical sectional 1view on the line 6-6 of -Figure 4, looking in the direction of the arrows.

Figure 7 is a fragmentaary sectional view on the line 1--1 of Figure 4.

Figure 8 is a fragmentary. sectional view on the line 8-8 of Figure 4.

Figilie 9'is a'. fragmentary plan of a spring plate such as shown in Figure 4,'but illustrating an- Figure 9, looking in the direction of the arrows.v

Figure 11 is a fragmentary sectional view on the line II-ll of Figure 9, looking in the direction of.the arrows.

Figure 12 is a fragmentary sectional view on the line I2-l2 of .Figure 9.

Figure 13 is a fragmentary sectional view on the line I3-l3 of Figure 9.

Figure 14 is a view showing a developed profile of a helical spring centering rib or ange from the point A to the point B, as shown in Figure 9.

Figure 15 is a fragmentary plan corresponding to Figure 9, but illustrating another embodiment of my invention.

Figure 16 is a fragmentary view, partly in elevation and partly in section, on the line I6-l6 of Figure 15, looking in the direction of the arrows.

VFigure 17 is a fragmentary sectional view on the line ll-Il of Figure 15, looking in the direction of the arrows.

Figure 18 is a fragmentary plan corresponding to Figure 15, but showing a further embodiment of my invention.

Figure 19 is a fragmentary sectional view on the line l9-l9 o'f Figure 18, looking in the direction of the arrows.

Figure 20 is a fragmentary plan corresponding to Figure 18, but showing an additional embodiment of my invention.

Figure 21 is a fragmentary sectional view on the line 2 I-2l of Figure 20, looking in thedirection of the arrows. A

Figure 22 is a fragmentary sectionalview on the line 22-22 of Figure 20, looking in the direction of the arrows.

Figure 23 is a fragmentary plan corresponding v Referring to the drawings in detail, like parts.

being designated by like reference characters, and iirst considering the embodiment of my invenv2 v tion illustrated in Figures 1 to 8, inclusive, there is shown a portion offa railway truck I involving `a pair of side frames 2, only one of which is illustrated, receiving the ends of a bolster 3, only one end of which is illustrated. The bolster 3 extends into the window openings 4 of the frames 2, each window opening being defined by a compression member 5, a tension member 6, and bolster guide columns 1. Supported at each end on the tension member of a frame beneath the window openings 4, in the present embodiment, is a spring plank 8 between each end of which and each'corresponding end of the bolster 3 is a nest of springs 9 disposed in the corresponding window opening 4.

In the present embodiment, each nest of springs e 9 comprises four helical or coil springs or spring units I and an elliptic or banded leaf spring, or series of leaf springs held together by bands, II. Each spring II, inthe present embodiment, comprises a stack or series of curved spring leaves I2 held together intermediatetheir ends by bands I3, the outer surfaces of which may be=slightly convex to correspond with the curvature of the secured leaves, and divided into upper and lower groups, withtheir end portions separated by end blocks I4, in accordance with the usual practice for full elliptic springs;

In order to center or hold the ,elliptic and coil springs in proper position between the bolster and spring plank, or bolster and frame, if the spring plank is omitted, I employ preferably interchangeable upper and lower cast spring caps or plates I and I6, said plates being formed to surround or partially house the spring bands, as well as being provided with collars I1 extending toward the collars on the associated plate, Aand normally surrounded by the associated coil or helical springs for centering purposes. 'Ihe spring plates also directly engage the adjacent ends of the coil springs, and are thicker at these places than the remaining web portions of the f plate, thereby Providing elevating seats for said springs which are closer to one another than the seats for the elliptic spring bands, thereby avoiding over-stressing the leaves of said elliptic spring or allowing for a greater travel of said spring than would otherwise be permissible.

Each plate or cap I5 and I8 comprises the relatively thick corner portions I8 which serve as the seats for the helical springs III, as previously menl tioned. In the present embodiment, the collarsor flanges I 1 extending froml said seats for centering the helicalsprings I0 are defined by apertures I9 which flare both ways fromthe face of the plate from which said collars extend, as illustrated most clearly in Figure 7,` thereby conserving material and at the same time maintaining adequatestrength. The thickened portions I3|of the plate are for the same reasons desirably relieved by grooves 28 immediately surrounding the collars The corner portions I8 are desirably flattened 'jat the sides, as indicated/at 2|, so um they wm nt between the upstanding flanges 22 of the associated spring plank 8 with the desired clearance. The web 28 of the plate I5 or I8, as the case may be, between the corner portions I8, is desirably thinner than the corner portions, but made adequately strong by ribbing, generally indicated by Athe referencelcharacter 24, thereby conserving material. The central portion of the ribbing 24 is generallylrectangular, as indicated at 25, and

the web portion 28 surrounded by the rectangular ribbing 25, which forms lateral restraining means for the associated band I3, is still thinner in 'the width of the spring leaves or leaf springs of said elliptic spring II. Said straight portions 21 have their ends joined-by portions 28 which are considerably higher than the portions 21, as they may be on account of being beyond the sides of the leaves of said elliptic spring II. Said higher portions 28 comprise not only end portions but angular extensions aligned with the lower side portions 21, whereby the corner portions of each band are engaged by relatively tall centering ribs or flanges, the extreme end portions of which are adapted to engage the sides of the adjacent spring leaf. whereby the elliptic or banded leaf spring is eiiiciently centered or held in proper position.

Reinforcing ribbing or flanges desirably extend outwardly from the ends of the relatively tall ribbing 28 and' curve to lsubstantially align with the diagonals between opposite spring centering collars I1, where they unite with the relatively thick corner portions I8, as indicated at'29. Ribbing 30 yalso extends generally tangent to the generally circular corner portions I8 andv parallel` plank 8, which corrugations are formed to provide for interlocking of said plank with the auxiliary reinforcements 36 which are disposed in the lower corners of the windowiopening 4, as described and claimed in the Barrows Patent No. 1,652,808 of 'December 13, 1927, or directly with said reinforcements upon omission of the plank. 'Ihe bolster, plank, or frame-engaging surface of each plate is desirably generally flat, as illustrated, thereby providing a satisfactory shimming surface.

Referring now to the embodiment of my invention illustrated in Figures 9 to 14, inclusive, there is disclosed a cast spring plate I5Il which is only fragmentarily illustrated, as said plate is symupper element of the section line III-I8. 'I'he plate I5 differs from the plate I5 of the previous metrical about the center line represented by the A embodiment, in that the corner portions I8* serve to center associated helical springs by peripheral preferably serrated ribbing |11, which may be entirely discontinued where the corner portions are flattened at the sides, as indicated at 2I.

- The manner in which the centering flanges I1- vided with relief grooves'20 and apertured at II.

In the present embodiment, the central portion ofthe web 28l is formed with a generally positioning an associated elliptic spring by surrounding the engaged band thereof. 'I'he web portion 26a inside of said rectangular ribbing isI preferably generally thinner thanthe web portions outside of said ribbing and is desirably concave to match the engaging surface of an associated spring band.

As in the preceding embodiment, the rectangular band `positioning rib or flange 25EL comprises generally straight side portions 2la which correspond in height with the thickness of the band and extend distances corresponding with the width of the spring leaves of the associated elliptic spring. The straight portions 21a have their ends joined by portions 283a corresponding with the portions 26 of the preceding embodiment, which, in turn, are joined by curved portions 29a to the thickened portions I8, as in the preceding embodiment.

As in the preceding embodiment, the web 23a of each plate IEP- outwardly of the portions 28 and 29e is desirably extended diagonally upward or from the normal plane of the plate in the direction of the centering ribbing, as indicated at 3de, so as to provide for properly nesting with corrugations or reinforcements,` as in the preceding embodiment. The edges of the plate between thecorner portions are desirably rigidifled by ribbing or flanges 30E. which connect the adjacent ends of the serrated helical spring encircling ribs at the inclined portions 34a of the plate in the same way the edges of the plate are reinforced by peripheral ribbing 3Ia between the serrated flanges Il along the portions of the web 23EL outwardly of the ribbing 21.

Referring now to the embodiment of my invention illustrated in Figures 15, 16 and 1'7, there is disclosed a cast spring plate Iiib which is only fragmentarily illustrated as said'plate is symmetrical about the center line represented by the section line I'l-I'l and the upper element of the section line It-I6. The plate I5b differs from the plate I5 of the first embodiment in that'both the corner portions ith have helical' spring centering collars I1b and, while thicker than the web 2thof the plate, they do not have the relief grooves around the collarsand the ribbing 3|b is at the edge of the web portion instead of between said web portion and a gusset outwardly thereof. The edge of the web portion 23b is also rigidied by peripheral ribbing 3l)b extending around the diagonal portion 34h as in the embodiment of Figures 9 to 14, inclusive.

As in the first embodiment, rectangular ribbing 2lb, 28h is provided for centering an associated elliptic spring by surrounding the band thereof, but the web-portion 2Gb surrounded by said ribbing is ofthe same thickness as the web portion 23h outwardly thereof and is hat rather than being cylindrically concave on its upper surface. In the Apresent embodiment, the ribbing 28h is extended straight outwardly and tapered in depth to merge into the web 23h, as indicated at 29h, rather-than curving and extending to the thickened corner portions Ib. Except as specifically described, theplate oi the present embodiment may correspond with that of Figures 1 to 8,

inclusive.

Referring now to the embodiment of my invention illustrated in Figures 18 and 19, there is disclosed a cast spring plate I5c, which is only fragmentarily illustrated, as said plate is symmetrical about the vertical center line illustrated and the horizontal-center line represented by .the section line IS-I 9. The plate I5c is substantially identical with the plate I5a of the embodiment of Figures 9 to 14, inclusive, except that there is no flattening of the thickened corner portions II!c sufficient to cut away the peripheral spring positioning ribbing |10. A further distinction resides in'the fact that the curved ribbing 29c connects the ends of the straight portions of the ribs 28L with the thickened corner portions I 8 instead of the angular extensions of said ribs which are aligned with the ribbing 21e. Except as specifically described, the present embodiment may correspond with that of Figures 9 to 14, inclusive.

Referring now to the embodiment of my invention illustrated in Figures 20, 21 and 22, there is disclosed a cast spring plate I5d which is only fragmentarily illustrated, as said plate is symmetrical about the center lines represented by the section lines 2I-2I and 22-22. The plate I5d differs. from the plate of Figures 15, 16 and 17 in that the peripheral ribbing 30d and 3|d is generally parallel to the diagonals between opposite corner portions I8d rather than being curved, the inner portions of said ribbing, however, being connected by curved portions 31 and 38, respectively. A further distinction resides in the fact that the straight portions 29d of the ribbing extend from the angular ends of the relatively high ribbing 28d, which completes the rectangular spring band surrounding portion comprising the ribbing 21d, instead of being aligned with the ribbing 28d. In the present embodiment, the web portion: 26d surrounded by the ribbing 21d, 28d is thinner and preferably concavely curved on its upper surface like the web portion 26 of the first embodiment, rather than being flat like the web portion 26In of the embodiment of Figures 15, 16 and 17. Except as specifically described, the plate Iiid may correspond with the plate I5b of the embodiment of Figures 15, 16 and 17.

Referring now to the `embodiment of my invention illustrated in Figures' 23 to 26, inclusive, there is disclosed a cast spring plate I5e which is only fragmentarly illustrated as said plate is symmetrical about the center line represented by the uppermost element of the section line 24-24. The plate I5e differs from the plate I5 of the rst embodiment in that there is no flattening of the thickened corner portions Ie, and two nibs 33e rather than one are provided on the gusset portions 32. A further distinction resides in the fact that the web portion 34e of the plate extends outwardly from the top of the relatively high ribbing 28e instead of extending diagonally from the main web 23e of the plate, said web portion 34 being generally parallel to the web portion 23e, with the end portions, however, sloping toward the web portion 23e to finally merge therewith, as indicated at 39. As inthe embodiment of Figures 20, 21 and 22, the ribbing 28e has straight'y portions 29e extending straight out from the angular end portions of said ribbing, tapering and merging into the web portion 23e with the web portions 39. As in the first embodiment, the rectangular spring band centering ribbing is completed by straight ribbing 21e which is not as tall' as the ribbing or web connecting portions 28e of the plate. As in the first embodiment, the web portion 26e surrounded by the rectangular portion 21e, 28e is generally thinner and at least partially preceding embodiments. Except as specifically described, the present embodiment may correspond with that of the first embodiment.

, From the foregoing disclosure, it will be seen that I have devised a spring plate, represented by several embodiments, which is adapted to positively retain the associated band of an elliptic or plate spring in normal position. Although I have shown my plate as separate from the adjacent bolster, spring plank or frame, associated with both coil and elliptic springs, and both above and below said springs. it will be understood that I do not wish to be limited to this showing, as, for example, the helical spring centering collars or ribbing and/or the generally rectangular springband-positioning ribbing may bel formed integral on the bolster and/or spring supporting portion of the side frame, or spring plank if used, and the plates omitted, resulting in what amounts to a merger of said plates with the bolster and frame or plank. Other modifications may, likewise, oc-

.cur to those skilled in the art. As indicated in the embodiments, the coil springs may be centered by outer or inner flanges and the reinforcing ribbing on the web of the plate, bolster, spring plank or frame may be varied to'some extent.

y Although the coil spring seats or supporting vportions of the plates are shown thicker than the elliptic spring seats, I do not wish to be limited to this showing, as I contemplate forms in which the seats for the two forms of springs are of the same thickness, and also in which the seats for 4the coil springs are thinner than tlose for the elliptic spring or springs. It will also be understood that although the elliptic spring bands are shown centered and surrounded by generally rectangular ribbing, the smaller ribbing, as designated by the reference character 21 in Figs. 1 to 8, inclusive, may be omitted, leaving the larger or taller ribbing 28 only. with its angular extensions, or the ribbing may be otherwise discontinuous or segmental, with portions, however. desirably lying on all four sides o'f the associated spring band, for properly positioning the elliptic spring or banded leaf springs.

Although preferred embodiments of my invention have been illustrated, it.will be understood that additional modifications may occur to those skilled in the art within the spirit and scope of the appended claims.

I claim:-

1. A spring nest adapted for insertion in the bolster opening of a railway vehicle side frame for the support of an associated bolster comprising upper and lower plates formed to center both helical springs and leaf springs held together by band means, said plates for that purpose having relatively thick corner portions adapted to center said helical springs, and thinner web portions connecting said corner portions and provided with ribbing, said ribbing comprising rectangular generally central portions formed to center the bands of said leaf springs.

2. A spring nest adapted for insertion in the bolster opening of a railway vehicle side frame for the support of an associated bolster comprising upper and lower plates formed to 'center both helical springs and leaf springs held together by band means, said plates for that purpose having relatively thick corner portions adapted to center said helical springs, and thinner web portions connecting said corner portions and provided with ribbing, said ribbing comprising rectangular generally central portions formed to center the bands l of said leaf springs, those portions of the webs surrounded by said rectangular portions being generally thinner than the web portions outwardly thereof.

3. A spring plate for a truck spring unit provided with relatively thick corner portions adapted to center helical springs, and thinner web portions connecting said corner portions and provided with ribbing thereon, said ribbing comprising a rectangular generally central portion formed to center a band of an associated banded leaf spring.

4. A spring plate for a truck spring unit involving both helical and leaf springs held together by band means, said plate comprising relatively thick corner portions adapted to center said helical springs, and thinner web portions connecting said corner portions and provided with ribbing, said ribbing comprising a rectangular generally central portion formed to center a band of said leaf springs, that portion of the web surrounded by said rectangular portion being generally thinner than the web portion voutwardly thereof.

5. A spring plate for a truck spring unit comprising corner portions adapted to center helical springs, and web portions connecting said corner portions, said web portions having a generally rectangular rib with end portions of greater height than the sides in order to engage alongside the adjacent leaf of a banded leaf spring, as well as suroround the band of said spring.

6. A spring plate for a truck spring unit comprising corner portions formed to center helical springs, and a web portion connecting said corner portions. said web portion having reinforcing ribbing thereon disposed generally parallel to the diagonal axes through opposite corner portions.

7. A spring plate for a truck spring unit comprising corner portions formed to center helical springs, and a web portion connecting said corner portion, said web portion having ribbing thereon formed generally rectangular in plan for center- 'ner portions and provided with rectangular ribbing for centering a band of an associated banded -leaf spring, said corner portions being connected by ribbing extending over the face of said web, portions of said webextending outwardly of said ribbing, and nibs disposed, at least in part beyond said ribbing, for centering said plate.

9. A spring plate for a truck spring unit provided with corner portions adapted to center helical springs, and web portions connecting said corner portions and provided with ribbing generally rectangular in plan for centeringa banded leaf spring, that portion of said web inside of said rectangular ribbing being generally cylindrically concave to allow the band to nest therewith 1Q. A spring plate for a truck spring unit provided with corner portions adapted to center helical springs, and a web portion connecting said corner portions and provided with ribbing thereon, said corner portions having serrated ribbing around the periphery thereof for centering helical springs and uniting with ribbing on the connecting web portion of said plate.

l1. A spring plate for a truck spring unit pro- 12. A spring group for use in truck side frames comprising leaf springs held together by bands, said spring group being dei'lned at one end by a multiplicity of spring bearing surfaces, cast means providing a seat for, and with lateral restraining means lying on four sides of, a band, said cast means forming a' load carrying element of the truck, and a separate cast member for thel opposite end of Said spring group, said separate cast member embodying lateral restraining means lying on four sides of the other band of the.

group, the opposite face of said separate cast member being relatively fiat to afford a shimming surface.

13. A spring nest adapted for insertion in the bolster opening of a railway vehicle side frame for the support of an associated bolster comprising upper and lower plates formed to center helical springs and leaf springs 1field together by band means, said plates for that purpose having corner portions of a thickness differentifrom that of the remainder of the plate and adapted to ribbing, said ribbing comprising portions lying ,v

on all four sides of the band. means of said leaf springs.

14. A spring plate fora truck spring unit comprising corner portions adapted to center lill helical springs, and web portions connecting said corner portions, said web portions having ribs adapted to lie on four sides of the band of a leaf spring to prevent lateral shifting thereof, the ribs on two opposite sidesY being of greater height thanfthose on the other sides in order to engage alongside the adjacent leaf of said spring.

15. A spring plate for a truck springV unit provided with corner portions adapted to center helical springs and a web portion connecting said corner portions and provided with ribbing thereon. said ribbing comprising spaced relatively high side portions and spaced relatively low side portions lying on opposite sides of a generally rectangular seat fora band of an associated leaf spring, said ribbing serving to maintain said band in` proper position, said ribbing portions joining with tapering ribbing which finally merges into theweb portion of the plate.

16. A nest of springs adapted for insertion in the bolster opening of a; railway vehicle side frame to support an associated bolster, said nest comprising helical springs and leaf springs held together by band means, and means associated with said bolster and that portion of said frame beneath said opening for centering said helical springs and the band means of said leaf springs, said means includingcast ribbing lying on all four sides of each seat for the spring band means to prevent lateral shifting thereof.

17. A spring plate for a truck spring unit comprising corner portions formed with annular beading for centering helical springs. and a web portion connecting said corner portions, said web portion having reinforcing ribbing thereon at least portions of which are parallel to other portions, at least some of said reinforcing ribbing merging with ribbing adapted to lie on four sides of the band of an associated banded leaf spring for centering purposes.

18. A spring plate for a nest of bolster springs comprising helical springs and leaf springs held together by bands, said plate comprising corner portions of a thickness different from'that of the remainder of said plate and adapted to center said helical springs, and a web portion connecting said corner portions with ribbing, said ribbing comprising portions lying on four sides of the engaging band of said leaf springs.

19. A spring. plate including a body portionv having a centrally disposed spring band seat and coil spring seats spaced on opposite sides thereof, said spring band seat being defined by projections adapted to extend on each side of a spring band, a portion of said projections being offset to clear a tension member of a double truss side frame.

20. A spring plate including a body portion having a centrally disposed spring band seat and coil spring seats disposed on opposite. sides thereof, said spring band seat being defined by spaced lugs upwardlyoifset from said body portion, to clear a tension member of a double truss side frame.

21. A spring plate including. a body portion having a centrally disposed spring band seat and coil spring seats disposed on opposite sides thereof, said spring band'seat being defined by projections adapted to extend on each side of a spring band, a portion of said projections being offset to clear a tension member of a double truss side frame, said spring band seat being disposed at a diiferent level from said coil spring seats.

22. In a truck, the combination of a side frame including tension and compression members and integrally connecting columns forming a window therewith, a portion of vsaid tension member extending into said window, a load carrying member extending into said window and slidably cooperating with said columns, said load carrying'member having spaced coil spring positioning means disposed adjacent coil spring seats, a spring band seat between said' positioning means, a spring group including coil springs positioned by said positioning means, a leaf spring engaging said -band seat, said band seat being disposed at a different level from said coil spring seats, a spring plate carried by said side frame, said spring plate including a spring band seat engaging and supporting a band of said leaf spring, and spaced dowels disposed adjacent said coil spring seats received by said coil springs member having spaced dowels disposed adjacent coil spring seats, a spring band seat between said dowels, a spring group including coil springs positioned by said dowels, a leaf spring having a band engaging said band seat, a spring plate carried by said sideiframe, said spring plate including a spring band seat engaging and supporting a band of said leaf spring, and spaced dowels disposed adjacent said coil spring seats .received by said coil springs, said spring band seat being dened by spaced lugs embracing said spring band and including an upwardlyprojecting portion disposed to clear the portion of a tension member in said window and forming a centering means for said band.

24. In a truck, the combination of a side frame including tension and compression members and integrally connecting columns forming a window ltherewith, a portion of said tension member extending into said window, a load carrying member extending into said window and slidably cooperating with said columns, said load carrying member having spaced dowels disposed adspring band, a portion thereof being olset upwardly from the base of said spring plate to clear the portion of a tension member in said received by said coil springs, said last named coil window and forming a centering means for said band.

25. In a truck, the combination of a side frame including tension and compression members and integrally connecting columns forming a window therewith, a portion of said tension member extending into said window, a load carrying member extending into said window and slidably cooperating with said columns, said load carrying member having spaced dowels disposed adjacent coil spring seats, a spring band seat between said dowels, a spring group including coil springs positioned by said dowels, a leaf spring having a band engaging said band seat, and a spring plate carried and positioned by said side frame, said spring plate including a spring band seat engaging and supporting a band o! said leaf spring said band seat including an upwardly projecting portion disposed to vclear the portion of a tension member in said window and forming a centering means for said band.

a band engaging said band seat, a spring plate carried by said side frame, said spring plate including a spring band seat engaging and supporting ay bandol.' said leaf spring, and spaced dowelsv disposed adjacent said coil spring seats spring seats being disposed at a higher'level than said last named band seat said band seat includlng an upwardly projecting portion disposed to clear the portion oi a tension member in said window and forming a centering means for said band.

, DONALD 'L, TOWNSEND. 

